private static IEnumerable <IPdfPathItem> ConvertPolyline(DxfLwPolyline lwPolyline, DxfLayer layer,
Matrix4 affine, Matrix4 scale)
{
var pdfStreamState = new PdfStreamState(
strokeColor: GetPdfColor(lwPolyline, layer),
strokeWidth: GetStrokeWidth(lwPolyline, layer));
IList <DxfLwPolylineVertex> vertices = lwPolyline.Vertices;
int n = vertices.Count;
DxfLwPolylineVertex vertex = vertices[0];
for (int i = 1; i < n; i++)
{
DxfLwPolylineVertex next = vertices[i];
yield return(ConvertPolylineSegment(vertex, next, affine, scale, pdfStreamState));
vertex = next;
}
if (lwPolyline.IsClosed)
{
var next = vertices[0];
var p1 = affine.Transform(new Vector(vertex.X, vertex.Y, 0))
.ToPdfPoint(PdfMeasurementType.Point);
var p2 = affine.Transform(new Vector(next.X, next.Y, 0))
.ToPdfPoint(PdfMeasurementType.Point);
yield return(new PdfLine(p1, p2, pdfStreamState));
}
}
private static IEnumerable <IPdfPathItem> ConvertLine(DxfLine line, DxfLayer layer, Matrix4 affine)
{
var p1 = affine.Transform(line.P1).ToPdfPoint(PdfMeasurementType.Point);
var p2 = affine.Transform(line.P2).ToPdfPoint(PdfMeasurementType.Point);
var pdfStreamState = new PdfStreamState(
strokeColor: GetPdfColor(line, layer),
strokeWidth: GetStrokeWidth(line, layer));
yield return(new PdfLine(p1, p2, pdfStreamState));
}
private static IPdfPathItem ConvertPolylineSegment(DxfLwPolylineVertex vertex, DxfLwPolylineVertex next, Matrix4 affine,
Matrix4 scale, PdfStreamState pdfStreamState)
{
var p1 = affine.Transform(new Vector(vertex.X, vertex.Y, 0))
.ToPdfPoint(PdfMeasurementType.Point);
var p2 = affine.Transform(new Vector(next.X, next.Y, 0))
.ToPdfPoint(PdfMeasurementType.Point);
if (vertex.Bulge.Equals(0.0))
{
return(new PdfLine(p1, p2, pdfStreamState));
}
double dx = next.X - vertex.X;
double dy = next.Y - vertex.Y;
double length = Math.Sqrt(dx * dx + dy * dy);
if (length <= 1e-10)
{
// segment is very short, avoid numerical problems
return(new PdfLine(p1, p2, pdfStreamState));
}
double alpha = 4.0 * Math.Atan(vertex.Bulge);
double radius = length / (2.0 * Math.Abs(Math.Sin(alpha * 0.5)));
double bulgeFactor = Math.Sign(vertex.Bulge) * Math.Cos(alpha * 0.5) * radius;
double normalX = -(dy / length) * bulgeFactor;
double normalY = +(dx / length) * bulgeFactor;
// calculate center (dxf coordinate system), start and end angle
double cx = (vertex.X + next.X) / 2 + normalX;
double cy = (vertex.Y + next.Y) / 2 + normalY;
double startAngle;
double endAngle;
if (vertex.Bulge > 0) // counter-clockwise
{
startAngle = Math.Atan2(vertex.Y - cy, vertex.X - cx);
endAngle = Math.Atan2(next.Y - cy, next.X - cx);
}
else // clockwise: flip start and end angle
{
startAngle = Math.Atan2(next.Y - cy, next.X - cx);
endAngle = Math.Atan2(vertex.Y - cy, vertex.X - cx);
}
// transform to PDF coordinate system
var center = affine.Transform(new Vector(cx, cy, 0)).ToPdfPoint(PdfMeasurementType.Point);
var pdfRadius = scale.Transform(new Vector(radius, radius, radius)).ToPdfPoint(PdfMeasurementType.Point);
const double rotation = 0;
return(new PdfEllipse(center, pdfRadius.X, pdfRadius.Y, rotation,
startAngle, endAngle, pdfStreamState));
}
private static IEnumerable <IPdfPathItem> ConvertCircle(DxfCircle circle, DxfLayer layer, Matrix4 affine, Matrix4 scale)
{
var pdfStreamState = new PdfStreamState(
strokeColor: GetPdfColor(circle, layer),
strokeWidth: GetStrokeWidth(circle, layer));
// a circle becomes an ellipse, unless aspect ratio is kept.
var center = affine.Transform(circle.Center).ToPdfPoint(PdfMeasurementType.Point);
var radius = scale.Transform(new Vector(circle.Radius, circle.Radius, circle.Radius))
.ToPdfPoint(PdfMeasurementType.Point);
yield return(new PdfEllipse(center, radius.X, radius.Y, state: pdfStreamState));
}
private static IEnumerable <IPdfPathItem> ConvertArc(DxfArc arc, DxfLayer layer, Matrix4 affine, Matrix4 scale)
{
var pdfStreamState = new PdfStreamState(
strokeColor: GetPdfColor(arc, layer),
strokeWidth: GetStrokeWidth(arc, layer));
var center = affine.Transform(arc.Center).ToPdfPoint(PdfMeasurementType.Point);
var radius = scale.Transform(new Vector(arc.Radius, arc.Radius, arc.Radius))
.ToPdfPoint(PdfMeasurementType.Point);
const double rotation = 0;
double startAngleRad = arc.StartAngle * Math.PI / 180;
double endAngleRad = arc.EndAngle * Math.PI / 180;
yield return(new PdfEllipse(center, radius.X, radius.Y, rotation, startAngleRad, endAngleRad,
pdfStreamState));
}
private static PdfText ConvertText(DxfText text, DxfLayer layer, Matrix4 affine, Matrix4 scale)
{
// TODO horizontal and vertical justification (manual calculation for PDF, measure text?)
// TODO Thickness, Rotation, TextStyleName, SecondAlignmentPoint
// TODO IsTextUpsideDown, IsTextBackwards
// TODO RelativeXScaleFactor
// TODO TextHeight unit? Same as other scale?
// TODO TextStyleName probably maps to something meaningfull (bold, italic, etc?)
PdfMeasurement fontSize = scale.Transform(new Vector(0, text.TextHeight, 0))
.ToPdfPoint(PdfMeasurementType.Point).Y;
PdfPoint location = affine.Transform(text.Location).ToPdfPoint(PdfMeasurementType.Point);
var pdfStreamState = new PdfStreamState(GetPdfColor(text, layer));
return(new PdfText(text.Value, Font, fontSize, location, pdfStreamState));
}
private static IEnumerable <IPdfPathItem> ConvertPoint(DxfModelPoint point, DxfLayer layer, Matrix4 affine, Matrix4 scale)
{
var p = affine.Transform(point.Location).ToPdfPoint(PdfMeasurementType.Point);
var thickness = scale.Transform(new Vector(point.Thickness, 0, 0)).ToPdfPoint(PdfMeasurementType.Point).X;
if (thickness.RawValue < 1)
{
thickness = PdfMeasurement.Points(1);
}
// TODO fill circle? For now fake it via stroke thickness.
var pdfStreamState = new PdfStreamState(
strokeColor: GetPdfColor(point, layer),
strokeWidth: thickness);
yield return(new PdfCircle(p, thickness / 2, pdfStreamState));
}
public PdfSetState(PdfStreamState state)
{
State = state;
}
public PdfArc(PdfPoint center, PdfMeasurement radius, double startAngle, double endAngle, PdfStreamState state = default(PdfStreamState))
: base(center, radius, radius, startAngle: startAngle, endAngle: endAngle, state: state)
{
}